Means for producing fine sinter returns



MEANS FOR PRODUCING FINE SINTER RETURNS Filed April 27, 1931 2 Shets-5heet 1 WW I @7 ALWELK W. SMMLLUCZK L85+ MEANS FOR PRODUCING FINE SINTER RETURNS Filed April 27, 1931 2 Sheets-Sheet 2 m 2 i! E R Ii LLLHL o c Q o o o 0 0 l an E o o o o o o o I I 1 I D o o o 9 o o o O [Mani a7" Edward h/Jfiall a ymmybmw Patented May 3, 1932 UNITED STATES PATENT OFFICE EDWARD W. SEAL-LOCK, OI CHICAGO, ILLINOIS, ASSIGNOR T0 AMERICAN ORE BECLAKATION COMPANY, OF CHICAGO, ILLINOI8, A CORPORATION OIvNEW YORK ms r03. rnonucme rmn smran nn'runns Application filed April 27,

The present invention relates to sintering machines for sintering finely divided ore, flue dust, and materials containing combustible ingredients, and has to do more particularly with a method of and means for producing fine sinter returns.

In sintering machines the material to be sintered is deposited upon agrate and is ignited, after which combustion is propagated throughout the mass-by causing passage of an air current through the same. In the well known Dwight and Lloyd type of sintering machine, to which myinvention is particularly adapted, a train of separate pallets, carrying the material to be sintered, are

moved along an endless track, the pallets on the upper run of the track traveling beneath a feed hopper from which the material is discharged onto the grate sections of the pallets. The pallets then pass beneath an ignition device which serves to ignite the material. During the continued travel of the pallets along the upper run-of the track, they pass above a succession of wind boxes by means of which a down draft is produced through v the material so that combustionis propagated downwardly through the mass. At the discharge or delivery end of the machinethe sintered material is discharged from the pallet. In general, the material to be sintered consists of fine particles commonly designated as fines, and relatively large or coarse particles commonly designated as aggregates, these materials being intermixed and deposited upon the grate of the pallet. The purpose of the fines is to increase the porosity of the mass to be sintered so that free passage of air may be had throughout the mass and in sufiicient quantity to assure quick and proper sintering thereof during travel'of the grate to the delivery or discharge end of the machine, as well as increased output of said machine. It is the present practice when sintering materials in continuously operating machines, such as the Dwight and Lloyd type, to obtain the fines from the sinter as it is broken up at the return bend or delivery end of the track, thesefines being separated from the sinter and used again in connection with the raw material. Such fines are com- 1981. Serial no, 583,150.

monly known as finesinter returns-. While such a method is satisfactory, I find that the amount of sinter returns obtained is relative- 1y small as compared to the amount needed 'to assure the most efficient operation of the sintering machine. I have found that if means 1s provided to loosen or break up the top of the sinter when the material is in a non-adhesive and more or less loose condi-' tion, that is to say at a time when the sinter mg operation is substantially complete and the stickiness and. tackiness of the material has disappeared, but before the sinter-takes its finalset, that substantially any desired amount of additional fine sinter returns may be obtained. One of the main objects of my invention is to provide simple and efi'icient means for producing sinter return fines to be mixed with the raw materials to be sintered. Another object of my invention is to provide means of the character described which can readily be applied to a sintering machine wlthout in any way interferring with the operation of said machine. A further obect is to provide means so positioned upon the machine that it will loosen or break up the top of the material being sintered when said material is in a non-adhesive or loosened conditlon. A still further object of my invention is to provide simple and efficientthis section being taken substantially on the line 2'--2 of Figure 3;

Figure 3 is a motion taken substantially on v the line 3-3 of Figure 1;

Figure 4 isa transverse vertical sectional" view of a continuously operating sintering Figure 5 is a plan view of the modified form of the invention illustrated in Figure 4..

I have illustrated my invention as applied, by way of example, to a sintering machine of the Dwight and Lloyd type, though it may be used in its broad er aspects with other types of machines. Such machines are well known in the art and heed not be described in detail here. Suffice it to say that the sintering machine comprises a main frame 1 to which are suitably secured rails 2, these rails forming tracks for the rece tion of rollers 3, of pallets 4, which are 0 known type. This machine has an endless track, comprising an upper run and a lower run, the pallets being elevated from the lower run to the upper run by any suitable means, such as sprocket wheels5. The pallets are propelled along the upper'run by said sprocket wheels and are each provided with a grate 6, of any suitable or preferred type, the pallets on the upper run being in contact so as to form a continuous ti'aveling grate structure. As the allets travel along the upper run of the trac they first pass beneath a feed hopper 7, by means of which the material to be sintered is delivered to the pallets, after which thepallets pass beneath a suitable device 8 for igniting the material. The pallets in their continue travel then pass over wind boxes 9 which are connected to suitable suction means for creating a downdraft through the mass or,

layer of material on the pallets. whereby combustion is propagated downwardly therethrough.

In the embodiment of the invention illustrated in Figures 1 to 3, inclusive, the means for producing the additional sinter returns is indicated in its entirety at 11, and comprises a flat metal'plate or'castin 12, which extends transversely of the sinter ed '13 and rests directly thereon. This plate is of substantially the same width as the sinter bed and has its lower portion inclined upwardly at an angle, as indicated at-14, in order that it may ride easily over any irregularities in the bed. The plate is provided with a plurality of holes 15 for the. reception of ins 16, the said holes being spaced a art an arranged in rows transversely 0 said plate so that the pins of each row will be staggered with respect to the pins of the preceding rows. These pins have a tight fit in the holes through which they pass and are adapted to pznetrate .the upper surface of the sinter d 13 for the purpose of loosening or breaking up the top of said bed as it passes beneath the plate 12. A narrow plate or strip 1''? is'disposed over each row of holes and the pins 16'are secured thereto in any suitable or preferred manner. The depth to which the pins 16 penetrate the sinter bed may be varied and wear on the pins is compensated for by lowering strip 17 in a suitable man ner, as by striking it with a hammer.

The plate 12 is disposed on the sinter bed 13 at a point where it will. loosen the material forming the bed when said material-is in a non-adhesive and more or less loose condition, that is, at a point where the sintering operation is substantially complete and the stickiness and tackiness of the material has disappeared,- but before the sinter has taken its final set. 'Ifind' that such a condition occurs in proximity to the third from the last wind box at the delivery or discharge end of the machine. I, of course, do not intend to limit myself to disposing the plate 12 in proximity to such wind box as it is possible that the above condition will vary in different machines. The point is that the plate should be so disposed upon the sinter bed that it will loosen the material thereof when it is in a non-adhesive and more or less loose condition.

Suitable tension rods 18 are employed .to hold the plate 12 in proper position upon the top of the sinter bed 13 and to ermit said plate to rise or fall as required. %hese rods, at one end, are pivotally connected at 19 to upwardly extending lugs 20, formed integrally with the plate12. At their other end, the rods are secured to a transversely extending shaft 21, this shaft beingjournaled at its ends in uprights 22, which are secured to the frame 1 in any suitable or preferred manner.

In Figures 4 and 5 I have illustrated a modified form of my invention. In this form of the device I have dispensed with the tension rods 18 and have provided a fixed plate 12a adapted for reception ofthe pins 16. This plate, does not ride upon the sinter bed 13, as does the plate 12, but is disposed above the pallets, and transversely thereof, and is rigidly secured at its ends to uprights 22a, by

bolts 23, these uprights being disposed at the outer sides of the track 2 and secured to the frame 1 in any suitable or preferred manner. It will readily be seen that this will provide a rigid mounting for the pins 1611 which are mounted in the plate 12a in the same manner as has heretofore been described in. connection with the pins 16 of plate 12. The pins 16a are carried by narrow strips 17 a, as before.

The material to be sintered is deposited upon the grate structure from the hopper 7 ,and passes beneath the ignition device 8 where it is ignited. When the material has lost substantially all of its stickiness and.

tackiness it passes beneath the plate carrying the loosening and agitating pins. These pins penetrate the bed of sintered material, from the upper surface thereof and effectively loosen such material to a predetermined depth. The action of the pins on the sinter thereacross and inasmuch as the pins carried by the plate are staggered, substantially the may be likened to that of a rake being drawn entire surface of the sinter will be loosened to the discharge end of the machine where it is broken up and discharged into a chute 24,

this chute having a suitable screen 25 dis posed therein in any suitable or preferred manner. Inasmuch as such screens are well known in the art it need not be described here in greater detail. As the sinter passes down.

the chute, the fines drop through the screen into a suitable hopper 26, from which they are removed and mixed with the raw material to be sintered.

While. I have described a preferred and satisfactory embodiment of my invention, it

will be apparent to those skilled in the art that changes may be made within the spirit and scope thereof. I, therefore, do not wish to be strictly limited to the forms of my invention disclosed except in so far as such limitations may be included in the appended claims.

What I claim is:

l. The method of producingfine sinter returns, which comprises sintering the material, and loosening the upper surface of the sintered material without weakening the main body of said material.

:2. In combination, in a sintering machine comprising a travelin grate structure, means for depositing upon 5x6 grate material to be sintered, means for igniting the upper surface of the bed of material, and a plurality of finger-like members dispeosed to penetrate the u per portion of the d to a predetermined depth and held against movement in the direction of travel of. the grate structure.

3. In combination, in a sintering machine comprising a travelinggrate structure, means.

for depositing upon t e grate material to be sintered, means for igniting the upper sur face of the bed of material, and a plurality of finger-like members dis sed to penetrate the u per portion of the d to a predetermine depth and held against movement in the direction of'travelof the grate structure, said finger-like members being so disposed relative to the igniting means as to loosen the upper portion of the bed of material while such material is in a comparatively soft and unset condition.

4. In combination in a sintering machine comprising a travelin grate structure, means for depositing upon 518 grate material to be sintered, means for igniting the upper sur face of the bed of material, a plate seating upon the surface of said material, a plurality of finger-like members carried by said plate and disposed to penetrate the upper portionof the bed to a predetermined depth, and means for holding said plate and said fingers against movement in the direction of travel of the grate structure.

5. In combination in a sinteringmachine, -a main frame, a traveling grate structure carried by said main frame, means for depositing upon the grate material to be sintered, means for igniting the upper surface of the bed of material, uprights secured to said frame, a plate seating upon the surface of said material, a plurality of finger-like members carried by said plate and disposed to penetrate the upper portion of said bed to a predetermined depth, and means connecting said plate with said uprights and holding said plate and said fingers against movement a in the direction of travel of the grate structure.

6. In combination in a sintering machine, a main frame, a traveling grate structure carried by said main frame, means for depositing upon the grate material to be sintered, means for igniting the upper surface of the bed of material, uprights secured to said frame, a transversely extending plate seating upon said upri hts and out of contact with said bed, sai plate being rigidly ueld against movement in the direction of travel of the grate structure, and a plurality of finger-like members carried by said plate and disposed to penetrate the u per portion of said bed to a prcdetermine depth.

7. In combination in a sintering machine comprising a travelin grate structure, means for depositing upon is e grate material to be sinter-ed, means for ignitin the upper sur-. face of the bed of materia a late seating upon the surface of said materia means comprising a plurality of pins carried by said plate and disposed to penetrate the upper portion ofthe bed to a predetermined depth, said. pins being disposed in rows, and the 6 pins of each row being staggered with respect to the ins of the next adjacent row, and

means or holding said plate and said pins against movement in the direction of travel 0 the grate structure. 1

8. In combination in a sintering machine comprising a travelin grate structure, means for depositing upon t e grate material to be sintered, means for ignitin the upper surface of the bed of'materia a late seating upon the upper surface of sai material, a p uralit 0 pins carried in said plate and dispose thebed. to a predetermined epth,,the depth of penetration of said pins belng ca able of being varied, and means for holdmg said plateand said pins against movement in the direction of travel of the grate structure.

9. The method of producing fine sinter returns, which comprises sintering the material until it is in, a substantially soft and unset condition, and then passing said mate topenetrate the u per portion of 10. The method of producing fine sinter returns which comprises sinterln rial until it has lost substantial y all of its stickiness and tackiness and thenpassing said material under means held against movement in the direction of travel of said material and thereby loosening the upper surface-of said material without weakening the main body of the material.

11. The method of producing fine sinter returns which comprises sintering the material until it is in a substantially non-adhesive and loose condition and then passing said material under means held against movement in the direction of travel'of said mate rial and thereb loosening the upper portion of said material before the materlal has taken its final set and without weakening the main body of said material.

12. The method of producing fine sinter returns, which comprises sinterin the material until it is in a substantial y soft and unset condition, and then loosening the upper portion of the bed of sintered material to a predetermined depth while itis in said substantially soft and unset condition, without weakening the subjacent portion of the bedof materiaL.

In witness whereof, I hereunto subscribe my name this 24th day of April, 1931.

' EDWARD W. SHALLOCK.

the mate- 

